add author/homepage/environment to build_test pubspec

Author: jakemac53

build_test/pubspec.yaml

@@ -1,8 +1,14 @@
 name: build_test
 description: Utilities for writing unit tests of Builders.
 version: 0.1.0
+author: Dart Team <[email protected]>
+homepage: https://github.com/dart-lang/build
+
 dependencies:
   build: ^0.3.0
   logging: ^0.11.2
   test: ^0.12.0
   watcher: ^0.9.7
+
+environment:
+  sdk: ">=1.8.0 <2.0.0"